Magnetic core package



Sept. 6, 1966 D. R. HARNER ETAL 3,271,747

MAGNETIC CORE PACKAGE Filed Aug. 22, 1961 INVENTORS DONHLD R. HaRNER BY Nmmu Puxxn M 'W W United States Patent Camp Hill, Pa., assignors to AMP Incorporated, Harrisburg, Pa.

Filed Aug. 22, 1961, Ser. No. 133,118 1 Claim. (Cl. 340-174) This invention relates to a magnetic core device assembly.

A primary object of invention is to provide a magnetic core package of a simple, compact and sturdy construction.

A further object of invention is to provide a magnetic core package which, while adequately protecting cores and windings from damage incident to handling, will permit access to cores and windings for inspection and/ or alteration.

A still further object of invention is to provide a magnetic core package of a construction readily adaptable to core arrays of considerable length.

An additional object of invention concerns the provision of a core package having incorporated therein recirculating conductors of improved transmission characteristics.

In US. Patent No. 2,995,731 to I. P. Sweeney there is disclosed a magnetic core device comprising an array of multi-aperture magnetic cores arranged in two columns and connected to produce a shift register function. The construction of the unit of that application simplifies production by facilitating core winding. The core arrangement, wiring and operation of the device of the present invention may be similar to that of the Sweeney patent with the advantages obtained thereby.

In handling units of the type shown in the abovementioned application, certain problems have arisen due to damage of cores and windings. While potting of the assembly generally eliminates core and coil mis-alignment due to handling it does not preclude fracture of a core by reason of tools or other objects being dropped thereon and, in fact, increases the likelihood of winding breakage in the event of bending or twisting of the core mounting panel. Moreover, potting makes it impossible to either inspect or alter cores or windings once the potting material has hardened. The present invention contemplates a construction comtpletely covering the cores and windings with a hard but resilient cover thereby eliminating damage from objects dropped on the assembly or from other cause incident to handling. Additionally, the package of the invention substantially strengthens and rigidities the core mounting board and permits core and winding inspection and/or alteration during the life of the unit.

Many computer applications require a relatively large number of digit columns, thereby necessitating core arrays of 50 to 100 core bit length. It will be readily perceived that core assemblies of such length, mounted on a single board, greatly increase the bending and twisting moment placed upon the unit during handling. With the present invention, magnetic core devices of large bit lengths can be packaged in a manner precluding bending or twisting of the core mounting board.

In magnetic core assemblies of the type disclosed in the Sweeney patent it is frequently desirable and in certain instances necessary to provide recirculating conductors linking the output of such units to the input thereof. The installation of recirculating conductors poses a problem both as to placement on the core mounting board and with respect to transmission line considerations. The present invention provides a solution to these problems by incorporating into the core package thin,

flat copper conductors having an ideal transmission characteristic for magnetic core devices of the parallel row type.

Other objects and attainments of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawing in which there is shown and described an illustrative embodiment of the invention; it is to be understood, however, that this embodiment is not intended to be exhaustive nor limiting of the invention but is given for purposes of illustration in order that others skilled in the art may fully understand the invention and the principles thereof and the manner of applying it in practical use so that they may modify it in various forms, each as may be best suited to the conditions of a particular use.

In the drawing:

FIGURE 1 is a plan view of a prior art ten-bit core array with windings removed for clarity.

FIGURE 2 is a reverse plan view of the unit of FIG- URE 1.

FIGURE 3 is a perspective of a ten-bit core array packaged in accordance with the invention.

FIGURE 4 is a plan view of the unit of FIGURE 3.

FIGURE 5 is a section of the unit of FIGURE 4 taken along lines 55.

FIGURE 6 is an elevation of the center post employed in the unit of FIGURES 3-5.

FIGURE 7 is a longitudinal section of the bottom panel of one embodiment of the invention taken along the lines 77 of FIGURE 8 and enlarged for clarity.

FIGURE 8 is a reverse plan of the panel of FIG- URE 7.

FIGURE 9 is a perspective of a unit exemplifying the adaptability of the invention for core array packages of considerable length.

The magnetic core device shown in [FIGURE 1 is included principally to further explanation of the invention. This unit includes a core mounting panel 20, carry. ing in slots a plurality of vertically disposed magnetic ferrite cores 22 in a staggered relationship. Control and coupling windings are omitted for clarity but, as heretofore mentioned, could be as disclosed in the Sweenly patent for a shift register function. It is understood that the invention has utility with any similar array of cores having various and other functions and wiring schemes. Input and output windings 24 and 26 are shown coupling the end cores of the core array. FIGURE 2 represents the device of FIGURE 1, rotated top to bottom, and shows the cores 22 protruding through the panel 20 with recirculating conductors 3d, of a prior known type, supported by posts .36 in an overlying relationship to one row of cores 22. The winding 84 is connected to the last core of the core array through a minor aperture thereof, so as to produce a signal output representative of the core magnetic remanenw condition via conductors 30 to winding 32, coupling the major and minor aperture of the first core of the array. In this manner the output of the core array is recirculated.

In computer applications requiring large digit columns, the board 20 and conductors 30 must be extended many times the bit length shown in FIGURE 1, to provide for the increased function. One method of accomplishing this has been to connect a plurality of ten-bit stages together. Another method employed has been to mount the cores and windings 011 a single central board, such as 20 in FIGURE 1, with recirculating conductors 30 extending the length of the core columns. The former of these ap proaches requires an additional mounting frame and the latter is not sufiiciently resistant to bending without a center panel so thick as to interfere with core winding.

generate the output signal to avoid malfunction.

In both of the foregoing arrangements, general operational tion are encountered proportional to the length of a core array. These difficulties are due to the low characteristic impedance of a typical core array relative to the characteristic impedance of parallel wire recirculating conductors. The difference in match between core array and recirculating conductors results in a loss proportional to the mis-match factor times the loss present in a properly terminated line of the same length. This loss is such, that in a 50 bit length shift register having parallel wire recirculating conductors, it has been necessary in the past to re- This increases unit cost and reduces reliability due to the inclusion of the additional non-magnetic components necessary to regenerate the recirculated coreoutput signal.

The device of FIGURES 1 and 2, while quite satisfactory in operation in ten-bit core lengths, exposes cores, windings and recirculating conductors to damage during handling and permits tampering. Potting material bedded over the cores and windings does not provide a completely satisfactory solution to this problem for the reasons heretofore mentioned.

FIGURES 3-6 show an embodiment of the package contemplated by the invention overcoming the foregoing problems. In FIGURE 3, the general feature of the package includes a central core mounting board panel 50 similar to that of panel 20 of FIGURE 1 and the aforementioned Sweeney patent carrying a plurality of ferrite magnetic cores 46 extending through the panel. Mounted proximate the ends of panel 50 are two central posts 60 and four side posts 48 extending through the panel to support top and bottom panels 42 and 44. The panels 50, 42 and 44 and the posts 60 and 48, in a preferred embodiment, consist of epoxy glass material approximately A of an inch thick. It is contemplated, however,

that any insulating non-magnetizable material sufficient- 1y strong to resist bending can be employed. It will be apparent that the panels 42 and 44 provide an area facilitating handling of the unit and an additional area whereon identification markings and instructions may be printed.

FIGURE 4 indicates that the panel member 42 extends to protectively cover the cores and windings from contact with objects such as cables or tools dropped or rested on the unit. Panel 44 of a similar dimension is mounted to cover the cores on the other side of the unit and both panels are supported and held by the cooperative action of center posts 60, carrying locking erings 52, which operate to snug down the panels on side posts 48 as more clearly shown in FIGURES 5 .and 6. The combination of panels and posts form a structurally strong unit capable of resisting both bending and twisting moment.

In situations wherein it is desirable to lock panels 42 and 44 to prevent tampering, phenolic or epoxy cement may be spotted over the posts 60 in place of e-rings 52. The posts 48 and 60 may also be spotted with cement at their juncture with the panel 50 to insure rigidity of the package.

In FIGURE 5, the relationship of panels 42, 44 and 50 to the posts 48 and 60 is shown with the panels 42 and 44 resting upon the posts 48 and locked into place by e-rings 52 fitted under the flange 54 of post 60 (as shown in FIGURE 6). Flange 62 serves to support the panels in proper vertical alignment and to further brace the assembly. For inspection and/or alteration of the cores and windings of a core assembly, the panels 42 and 44 may be removed by removing the e-rings 52 and lifting off the panels.

FIGURES 7 and 8 exemplify a form of outer panel which may be used in lieu of the solid plastic panels 42 and 44 above when recirculating conductors are rewere cemented therein.

' of core arrays quired. The panel 70 of FIGURE 7 is enlarged to show the conductor strips. The panel 70 of FIGURE 8 approximates dimensionally the actual size of a panel constructed for a ten-bit length shift register. In FIGURE 7 element 70 represents a stilf plastic non-magnetizable panel having mounting holes 72 at each end similar to holes 64 shown in FIGURE 6 to accommodate center posts 60. Recessed within the panel 70 are two flat copper strips and 82 separated as indicated by strips of insulation 86 and connected to each conductor at each end thereof by leads 76 and 74. In FIGURE 8, the conductors 80 and 82 are shown as of different lengths to facilitate the solder connection of leads 74 and 76. The leads 74 and 76, representing the ends of the conductors wound on the input and output core of a core array similar to windings 32 and 34- shown in FIGURE 2, should bepof a length sufficient to permit removal of the panel 70 without breaking the solder connection to the conductors 80 and 82. The groove 85 shown in FIGURES 7 and 8 may be either molded with the panel or cut therein after the panel has been formed.

It is contemplated that the panel 70 can serve as either a top or bottompanel of a core package, but for the usual wiring scheme, a bottom placement is preferred. It is further contemplated that the conductors 80 and 82 can be made to extend the full width of the panel with alternate layers of dielectric of a thickness to form in combination a structure of suflicient strength to prevent breaking or twisting of the central core mounting board.

An embodiment of the invention typifying the advantages set forth above is shown in FIGURE 9 representing a 50 length core array. A single piece central core mounting board 94 and single piece top and bottom panels and 92 are connected as heretofore disclosed by the cooperating engagement of side post 98 and center post 96 provided at each decade bit length. Input terminals 100 and output terminals 102 are provided at each end of the assembly.

In an actual prototype 50 bit length package similar to the unit shown in FIGURE 9, the panels were constructed of inch epoxy glass sheet drilled and slotted to accommodate core central and side posts and terminal posts. The bottom panel of the unit, panel 92 of FIG- URE 9, was cut to a depth of approximately &2 of an inch in the manner shown by recess 85 in FIGURE 8 and two strips of preinsulated copper sheet, 6 mils thick and 200 mlis wide, known commercially as Tape-Cable, The cores of the unit were wound with the end cores including recirculating windings soldered to the conductors in the bottom panel. The panels were installed and locked by e-rings as shown in FIGURE 4 above. The unit showed substantial resistance to either bending or twisting and the panels adequately resisted physical shock applied thereto. Under test, the unit operated with excellent results using the standard coreoutput signal achieving low recirculation loss without requiring regeneration of the core output signal.

, A core package constructed in accordance with the foregoing disclosure lends itself to economic mass production and provides a sturdy and reliable magnetic core device capable of manufacture in various lengths. The use of flat copper strips in lieu of parallel wire conductors so improves the impedance match between the recirculating transmission line and the core array that substantial :core 'lengths may be operated with normal voltage and current parameters. It is, of course, understood that the factors controlling the characteristic impedance of the recirculating conductors, such as, conductor spacing and/or dielectric material and conductor cross sectional area and shape, can be variously manipulated to achieve a sufiiciency of match for various types It will be apparent to those skilled in the art that use of flat conductors in addition to improvingimpedance match also reduces the possibility of 5 intra-inductive coupling with cores and windings by reason of the increased skin area of the conductor and its physical shape.

It will be further apparent to those skilled in the art that the foregoing package can be employed to protect a core assembly and/or provide improved recirculating conductors in core devices, wherein the cores are mounted parallel to the core mounting board on one side only or on both sides thereof.

Changes in construction will occur to those skilled in the art and various apparently different modifications and embodiments may be made without departing from the scope of the invention. The matter set forth in the foregoing description and accompanying drawing is offered by way of illustration only. The actual scope of the invention is intended to be defined in the following claim when viewed in their proper perspective against the prior art.

We claim:

In a magnetic core device of the type utilized to store and shift intelligence the combination comprising a core mounting panel, a series of magnetic cores mounted thereon, windings linking said cores including an input and an output winding linking the first and last of said plurality of cores and coupling windings linking adjacent cores to transfer intelligence stored in said cores between cores, at least another panel secured to said first mentioned panel in an overlying protective relationship to said cores, a recirculating loop linking the last core to the first core through the said output and input windings to recirc-ulate intelligence transferred through said register, the said recirculating loop being comprised of fiat conductors insulated from each other secured in said other panel to form a flat strip transmission line matched in impedance to the input and output impedance characteristics of the input and output cores and windings whereby to transmit recirculated intelligence with minimum signal loss.

References Cited by the Examiner UNITED STATES PATENTS 2,901,736 8/ 1959 Sylvester 340-474 2,934,748 4/1960 Steimen 340-174 2,985,948 5/1961 Peters 340-174 X 2,995,731 7/1961 Sweeney 340-474 3,051,930 8/1962 Austen 340174 3,130,134 4/1964 Jones 340-174 BERNARD KONICK, Primary Examiner. IRVING L. SRAGOW, Examiner.

R. I. MCCLOSKEY, M. S. GITTES, Assistant Examiners. 

